Method of and apparatus for drawing sheets of glass.



M 885,896. PATENTED APR. 28, 1908.

I H. J. WALTER. METHOD OF- AND APPARATUS FOR DRAWING SHEETS 0F GLASS.

I APPLICATION FILED JUNE 26. 1907.

2 SHEETS-SHEET 1.

I ZNVENTOR,

PATENT D 111 3.28, 1908.

I H. J. WALTER.

METHOD OF AND APPARATUSFOR DRA ING SHEETS 0F GLASS.

APPLIOATION IILBD JUNE 26. 1907.

' 4 2 SHEETSSHBET 2.

A TTORNEi S I/VITNESSESJ I 1 x J g6 HUGO J. WALTER, OF KANE, PENNSYLVANIA.

Specification of Letters Patent.

METHOD OF AND APPARATUS FOR DRAWING SHEE'TS OF GLASS.

Patented April 28, 1908.

Application filed June 26, 1907. Seria1.No.380,882.

To all whom it may concern:

Be it known that 1, HUGO J. WALTER, a citizen of the United States,,resid1ng at Kane, in the county of McKean and State of,

Pennsylvania, have invented a new and useful Method of and Apparatus for Drawing Sheets of Glass, of which the following is a specification.

This invention relates to the manufacture of sheets of glass by the drawing process.

In the manufacture of sheets of glass in this manner it is usual to employ a bait of suitable size and shape which is lowered into a body of molten glass, and then raised. in a vertical line, the molten glass clinging thereto in the form of a sheet. Owing to the nature of the material and the atmospheric pressure to which it is subjected, the sheet will gradually narrow in Width and reduce in thickness until finally it becomes a mere thread at the center, and it has been found practically impossible to produce sheets of arge size.

The principal object of the resent invention is to prevent this gradua narrowing of the sheet and to form a sheet of uniform width and of any desired length.

A further object of the invention. is to provide means for engaging and supporting the edges of a sheet of glass during and after its formation.

A still further object of the invention is to provide means for reducing the atmospheric pressure at the edges of the sheet, thus eliminating one of the factors which results in narrowing the sheet. v

A still further object of the invention is to provide means which will tend to spread or stretch the sheet in the direction of its widtli during the drawing operation.

A still further object of the invention is to provide means for producing a partial vacuum at the edges of the sheet being formed.

Astill further object of the invention is to. provide a glass drawing mechanism in which sup'orting strips are arranged to engage wit 1 the edge of the sheet during the drawing process.

A still further object of the invention is to provide a mechanism in whichthe o posite edges of the sheet are engaged. by pe orated metallic strips which will permit of the exhausting of air at the edges of the-sheet, so that the latter will tend tostretch laterally and will be made of uniform width throughout.

With these and. other objects in view, as will more fully hereinafter a ear, the invention consists in certain novel features of construction and arrangement of parts,.herein after fully described, illustrated in the accompanym drawings, and particularly pointed out in t e appended claims, it bein understood that various changes in the ornl,

. proportions, size and minor details of the structure may be made without departin from the spirit or sacrificing any of the a vantages 0 the invention.

In the accompanying drawingsz-Figure 1 is a sectional elevation of'a glass drawing machine embodying the invention. Fig. 2 is. a side elevation of' the same. Fig. 3 is a sectional plan view on the line 3-:3 of Fig. 1. Fig. 4 1s a sectional View illustrating the operation of drawing a sheet of glass.

Similar numerals of reference are employed to indicate corresponding arts throughout the several figures of the rawings.

The machine is arranged to be movedover a dog house or extension 10 on the nose of a glass tank or furnace, any well known'means' being employed for maintaining a cally constant level of molten glass in t e dog house, and the machine is preferabl mounted on over-head rails or supports, so t lat it may be moved to clear the furnace in order to per-- mit the convenient removal of the sheet or sheets of glass. 1

The mechanism comprises generally a casing or drum 15 which may be formed of cast metal and includes abody portion 16 and a top or cover 17, the central portion of the latter being provided with a stuffing box 18 for the passage of a hollow pistonrod'lt), any suitable means being employed for raising and lowering the piston rod. 7

To the lower end of the piston rod is secured a hollpw piston bait20 having a perforated bottom 21 which is lowered into con- -tact with the molten glass, and to which the glass clings when a partial vacuum iscreated within the piston by drawing out the air through the hollow piston rod 19, the latter having a suit-able nipple 22 which may be attached by a flexible-pipe or hose to any suitable [air exhausting apparatus.

Secured to the opposite-ends of the piston -20 arevertically disposed rods 23 that are preferably of rectangular form infcross section, the oppositeledgesof the rod fitting racti- J within vertical grooves formed in the casing in order to dipnde the" atter intoacentral piston bait.

port and remain idle until the s chamber 24 and two side chambers 25. The up or ends of the rods pass through suitu e stufiing boxes 26 curried by the cover, and these rods move up and down withthe piston.

The two chambers are placed in communication with any suction pump or air exhaustion apparatus through piping connections 255, end the central chamber 2e is also connected to an exhausting opp uretus, so that d nrtiulvecuuin may be created in all of'the chambers, as well us in the hollow Secured to the opposite ends of the casing hangers 33 in which are mounted sheaves 34: over Whioh'puss fist s'cel strips 35, one end of each strip being connected to the end of the piston, while the opposite end of the strip carries a weightor epr' 1g 36 which tends to hold. the strip tout st nl times.

Extending through ghe shoulders 25 in contact with the outer feces of the rods 23 are ammonia expansion coils 40 which. may be connected at the too of the cover with circulating pipes ll. T lower ends of the coils bend around under the lower mouth of the casing and extend upward adjacent to and follow the lines of the inclined portions of the steel strips 35, these coils being for the purpose of cooling the strips to a certain extent for the purpose of preventing the fusion of the stri s and their permanent attachment to the g ass.

, in operation, the bait is lowered until it engegeswith the body of molten glass, and then the air is exhausted in the bait and in the several chambers through the suction means referred to, after which tie piston bait is drawn upward. 'llie molten glass clings to the: bait and is drawn upward in the form of s sheet. As the piston moves up the rods 23 travel with it and still form partitions which separate the central chumher 24 from the side chambers At the some time the flexible perforated strips are drawn upward with the l.. uitnnd engage with the edges ol the sheet being formed. As the perforations of the strip follow 11) between the c-l'iambors 24 and 2a, the air will be drawn through the perlorutions and the glass will cling to therstrips and will tend to stretch laterally, the body of glass being supported and held from running down to o Q6111 trul thread.

As the sheet is using formed successively fresh portions of the perforated. strips hecome uttuclied to the edges of the sheet, so that the letter is maintained at uniform Width. during the entire drawing operation and sheets of any length may be successfully drawn. After it sheet of the required. lengtl'i has been drawn, its lower end is severed by knives or other suitable means, and the machine may be shifted lsterell on its suplieet cools to assess a sufiicient extent to permit its removul. The piston bolt may then be lowered, and us it movesdown the steel strips will be grudually separated therefrom, so that the nutchine Is in readiness for another droning operation.

In certain of the claims the term pneumotic means or penumutio su )poits is used for the purpose of designating the piston bull. which acts by rureluclion of the atmosphere to partly drew the glass thoreinto and the perforated side strips which by reduction of the air pressure on their outer lures not :is pneumstic supports for the edges of the sl'ieets.

I claima- 1. That improvement in. the art of droxwing sheets of glass, which consists in engaging and holding the full length of the edges of the sheet from inward movement during and after the-drawing operation by means applied exteriorly of said sheet.

That improvement in the art of drowing shoots of glass which consists in llloclutllicully supporting the edges of the shoots and reducing the atmospheric pressure at the edges, and in a line parallel with the two surfaces of the sheet independently of any variations in pressure on said surfaces.

3. That im rovement in the art of drowing sheets of g ass which consists in applying a support exteriorly to the edges of the shoot, as the drawing operation progresses, and continuously holding such su ports lrom inward movem nt for the full length ol' the sheet during and after the drawing operation.

4. In a glass druwing machine, menus for creating a. vacuum at the opposite edges of the sheet during the drawing operution independentlyof uny vuriutions in pressure on the surfaces of the sheet, the suction l'orcc thorcby crested tending to spread the shoot on lines 'umllel with the surfaces thereof.

5. n agluss drawing machine, menus for continuously supporting the edges of tho sheets during the drawing operation, and

continuous flanges of a. length equul at least to the full longthol the sheet und holding said supporting means from inward movement.

(3. in a glass drawing machine, supporting strips arranged to engage the edges of the sheet during the drawing operation, and continuous supports with which such strips on gage.-

7. In a glass drawing machine, flexible strips for engaging the edges of the sheet during the drawing operation, and means for engaging and holding the strips from in word movement after the glass leaves the pot.

8. In a glass drawing machine, ilexiblo strips for engaging the edges of the sheet during the drawing operation, and means cocx tensive with the length of the sheet for bolding the strips from movement toward each at icr.

ceases f in a glass drawing machine, flexible periorated strips for engaging the edges of tli. sheet during the drawing operation 1'- -.-'.-0.-."In. a glass drawing machine,- flexible perforatedisupporting strips arranged to engagetheiedges of the sheet during the draw-. '11! -operation,,a1id a vacuum chamber into oh the sheet. and strips pass to thereby reduce atmospheric pressure; on the edges of able ,wi

the stri s'.' g

12. n a glass drawmg mach1ne,'a'pneumatic bait and pneumatic strips for enga ing the. edges hi the sheet. g

13. 111 a glass drawing machine,-pneumatic supports for three edges of the sheet.

'14. Inaglass drawing machine, pneumatic supports for engaging a plurality of edges of the shee 15. In a glass drawing machine, a pneumatic bait. piston, perforated flexible strips having one end secured thereto, and means for maintaining the strips taut. 16. In a glass drawing machine, a casing hav' side vacuum chambers, a piston bait .niova le through the casing, and flexible sup- ,{porting strips-carried by the opposite endsof i: thejpiston, said strips being perforated.

. tlons between such chambers, a piston carry- 117. In a glass drawing machine, a casing having a central and s1de vacuum chambers, vertically disposed rods forming the partiing said rod, and edge engaging strips carried by the )iSiLOIl and arranged to support the edges o vthe glass sheet.

18. In'a glass drawing machine, a casing, a

hollow piston bait movable therein and provided with a perforated bottom, a hollow rod carrying the piston. and provided with a suction being-grooved for the reception of such'rods, and the rods dividing the casinginto a central andsidefehmpartinents, suction pipe connectionsigtor the; several compartments, flexible ".atedI'strips having one endsecured to means'for' engaging the edges of the sheet,

' and means for cooling said su plporting means.

20,111.21, glass drawing mac ine, edge sup- &

v ipe connection, a pair of rods or bars se-' cure tQ th G p1ston,'the side wallsof the casing pistoms ulding sheaves for said strips, and Weightsconnectedtothe free ends of .saidstripsp, v 1.9. Inaglass drawing machine, supporting porting strips for the sheet, and cooling means forth'e supporting means.

21. In a glass drawing machine, edge supportin strips, and cooling devices therefor..; 22.. n a glass drawing machine, edge su 1 ,orting strips, and coils or tubes arran ed a Jacent thereto for the circulation o a refrigerant. n testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

' HUGO J. WALTER.

' Witnesses: p

J. E. MULLIN, J. T. TU IIY. 

